Abstract: The Snyder quarry preserves one of the richest assemblages of Norian theropods in the world, and
the second-most productive theropod locality in the Chinle Group. At least four coelophysid theropods are preserved at the Snyder quarry, based on tibiae. Most elements of these theropods are represented, including an incomplete skull and lower jaws, cervical, dorsal, sacral, and caudal vertebrae, a scapulocoracoid, ilia, ischia, femora, tibiae, a fibula, astragalocalcanea, and diverse carpals and tarsals. These specimens demonstrate that the Snyder quarry theropods pertain to the Revueltian theropod Eucoelophysis, only known from the type locality at Orphan Mesa 10 km to the east and Baldwin’s original collection described by Cope in 1881. Theropod dinosaurs at the Snyder quarry are the most abundant terrestrial predators, and outnumber rauisuchians and sphenosuchians. These theropods are, with the “Padian theropod” from the same unit in the Petrified Forest National Park and Procompsognathus from the Stubensandstein in Germany, part of an apparently Pangean radiation of coelophysid theropods during Revueltian (early-mid Norian) time.

Additional Information

Publication

Heckert, A.B., Zeigler, K.E., Lucas, S.G., and Rinehart, L.F., (2003) Coelophysids (Dinosauria: Theropoda) from the Upper Triassic (Revueltian) Snyder Quarry. New Mexico Museum of Natural History and Science Bulletin 24(Paleontology and Geology of the Upper Triassic (Revueltian) Snyder Quarry, New Mexico) p. 127-132. (ISSN 1524-4156) Archived in NC DOCKS with permission of the editor. The version of record is available at: http://econtent.unm.edu/